The main difficulty of Tsulong is the day phase, depending on your guilds' DPS capability, melee may / may not be on the primary big add (as opposed to the small adds on the outskirts). Depending on how good your healers are, you can use Healing Rain with 5 stack MSW to do massive raid healing in dark phase, or heal the boss during light phase (with sun breath).

Try save Shamanistic Rage and Astral Shift for dark phase, in case sun-beams get blown up by Dark of the Night, and make sure to use your Earthbind Totem to get clutch roots on the Dark of the Night spawns (So they don't blow up the beam). Making good use of Tremor Totem for Fright' fears will save your raid, and during progression this will happen fairly consistently.

During day phase, you can use your Capacitator Totem to stun fright spawns when the big add dies, coordinating stuns on the adds is really important because you can get 1 shot with bad RNG (Unstable Sha Bolt + Fright spawn damage), Call of the Elements + Capacitator Totem can allow you to get 2, 5 second stuns each sun phase.

Always pre-plan your movements during the dark phase, if there is a large distance between yourself and the beam, Spirit Walk and Spiritwalkers Grace so you can minimize DPS downtime, depending on how many Druids you have in the raid, you should ideally have a Stampeding Roar for every second Sunbeam refresh, and Spirit Walk for every third / fourth.

There aren't many things I can tell you about maximizing DPS as Enhancement, or DPS in general, however what you can do is: During the Dark / Night phase, make sure to watch Dark of the Night spawns and their position to the boss. Timing your Lava Lash to spread Flame Shock onto the Dark of the Night spawns, and then Fire Nova-ing will result in a solid DPS increase, and is still a single target DPS increase.

If you want to look at logs, this is my Rank 3 parse for Tsulong, was a really shit kill, could have potentially gotten rank 1 with DPS and healers not dying.

Make sure you keep your interrupt handy for the unstable sha bolts. Your interrupt being ranged, low CD, and you being melee (not having to stop casting) makes your interrupt literally the strongest one in the game for this fight. You should be dropping it as many times as humanly possible on the adds. You should absolutely be #1 on interrupts by a large margin.

Also, when he transitions from night to day, drop your HST during that little down time and toss a couple healing surges. You don't have anything else to do, and every little bit helps. Any other time when you happen to have downtime, drop that HST. It's a raindrop in the ocean, but even a single drop can break the dam.